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Posted By: highground Service Mast Drill Extension - 08/06/08 12:22 AM
Hello all,

So, this guy I worked for 15 years ago had this special tool for boring through the soffit and roof for a 2" service mast. It was more than just a hole saw extension which I am using now. Does anybody have such a gizmo, and is anybody still making it. Or is it something I need to weld up in the shop.

Thanks a Bunch
Posted By: Bill Addiss Re: Service Mast Drill Extension - 08/06/08 12:50 AM
I used to use a 4 - 6 ft long 1/4" drill bit to drill through and then used the holes (Top and Bottom) as pilots for a Holesaw.

Bill
Posted By: renosteinke Re: Service Mast Drill Extension - 08/06/08 01:05 AM
I've done that as well, but the pilot bit always seems to wander frown

One guy claimed to have welded a hole saw to a piece of 2" pipe, allowing for a better alignment. Maybe. Be interesting to see how he kept it sharp - my hole saws seem to survive but ONE encounter with the gravel on shingles ... and I'm still looking for an easy way to get the tar off them!

Now ... I just might ask a machine shop to bore a piece of 2 1/2" aluminum round to fit over a hole saw extension.
Posted By: macmikeman Re: Service Mast Drill Extension - 08/06/08 02:40 AM
I used to drill the soffits out until one day I tried using my roto zip with the saw guard removed. I trace the hole first using the plastic thread guard off the end of the conduit for a template. You do need to climb the ladder, but it works like a charm.
Posted By: Zapped Re: Service Mast Drill Extension - 08/06/08 12:45 PM
I use the same method as Bill - the long 1/4" bit as a guide hole. You just have to keep that baby super sharp to avoid wandering when you get to the angled roof sheet.

WD-40 works pretty good at getting the tar off of your bits if you don't want to pull the shingles before you start. Gasoline works even better, but the flamibility factor makes it impractical. Never clean a hot bit either way!
Posted By: sparkyinak Re: Service Mast Drill Extension - 08/06/08 02:37 PM
Originally Posted by Zapped
... WD-40 works pretty good at getting the tar off of your bits...Gasoline works even better, but the flamibility factor makes it impractical.


What do you mean the flamibility is not practical. Just spray, burn, wipe off. Pretty simple. It doesen't get any better then that. smile
Posted By: Helectric Re: Service Mast Drill Extension - 08/06/08 03:04 PM
I've seen these but they were home made at a local machine shop. They consist of a piece of intermediate conduit approx. 4 - 8' long with bushings pressed in each end. There is a 3/8" or 1/2" shaft that passes freely all the way through the pipe. The shaft is quite a bit longer than the pipe and is held centered by the bushings. On one end of the shaft is welded the sawed off end of a bit extension. This is where you attach the hole saw bit. The other end is chucked up in your drill. To use you just strap the conduit to the wall where your service mast will go, level it, chuck the shaft up to your drill, and go. It drills a perfectly aligned hole through both the soffit and the roof. Works great on spec homes where you can just punch them all out in a row.
Posted By: master66 Re: Service Mast Drill Extension - 08/07/08 02:00 AM
I also use a long 1/4" bit as a pilot. I use a hole saw on the soffit for a tight fit then I use a hole saw and a sawzall on the roof. The flashing covers the hole and making the top hole bigger allows you to move the mast around to get it plumb. There is a company that make a hole saw arbor that accepts 3/8 all-thread for extensions up to 10 feet. I have seen ads in the back of magazines like Electrical Contractor or EC&M.
Posted By: renosteinke Re: Service Mast Drill Extension - 08/07/08 06:11 AM
I like the way this idea is developing ... an extra-long guide, not only to line up the two holes, but to also locate them exactly where the panel needs them to be!

It's a bit of a change in our sequence .... the 'normal' way seems to be to place the panel first, and then decide where to place the holes .... and with this device, you would first place your mast supports, then drill, then set the box. Or, maybe, set the box, mark, remove box, drill, mount again.

Still, though, it looks like a great way to get it done better, quicker - and smarter!
Posted By: master66 Re: Service Mast Drill Extension - 08/08/08 01:51 AM
I always do the mast first. Then plumb up the meter socket with the mast attached. I can move the meter socket up and down and left to right to get it just where I want it. THEN I mount it. This is of course, is so long as the hole below the meter socket into the house is not critical.
Posted By: BigB Re: Service Mast Drill Extension - 08/08/08 02:26 AM
That's the way I have recently started doing it, set up the mast first. Then you can use an offset turned just right to give you the distance you need for your mounting straps or strut.

That said, we still have some where we have to mount the panel first. Today we did a 400 amp overhead. Mounted the panel, then I got out my brand new Fat Max laser plumb bob that I bought for laying out hi hats and plumbed for the 3" mast. Came out perfect.
Posted By: BigB Re: Service Mast Drill Extension - 08/13/08 03:28 AM
I am happy to report we did another service today, used the Fat Max after the loadcenter was mounted, it came out perfect again. I cut out a little cardboard circle to fit inside the hub, then marked it dead center and lined up the laser plumb bob with the mark.
Posted By: dilydalyer Re: Service Mast Drill Extension - 08/19/08 10:32 PM
I heard people call that tool a mast-out tool.2 inch hole-saw on a 2 foot bit wrapped with a 2 inch ridid.The rigid revolved freely,in other words you could hold on to the rigid pipe and pull the trigger on the driil and the hole-saw would spin but not the pipe........thought I saw them in parts houses later but not sure
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